On 13/07/2010, at 6:44 AM, Javier Guerra Giraldez wrote:
> let's try:
>
> function f()
> return function () end
> end
>
>
> v1 = f()
> v2 = f()
>
> print (v1 == v2)
> => false
>
>
> local function g() end
> function f() return g end
>
> v1 = f()
> v2 = f()
> print (v1 == v2)
> => true
>
>
> --
> Javier
Thanks Javier. I thought I should write a test to work it out, but I didn't come up with anything, certainly not that simple.
On 13/07/2010, at 6:48 AM, Henk Boom wrote:
> Yes. It's semantically different as well: in the first case a setfenv
> on one of the returned functions would not affect the others, since
> they are all separate objects, but in the second case setfenv would
> affect them all, since they are all the same object.
>
> henk
That makes sense too.
Thanks everyone! So here's the test I could have written from the start, now that it's obvious:
local function g() end
local function f() return g() end
for i = 1,10000000 do f() end
print(collectgarbage('count'))
$ time lua closure-test-1.lua
28.810546875
real 0m0.987s
user 0m0.980s
sys 0m0.004s
local function f() return function() end end
for i = 1,10000000 do f() end
print(collectgarbage('count'))
$ time lua closure-test-2.lua
41.5634765625
real 0m2.850s
user 0m2.841s
sys 0m0.004s
Cheers,
Geoff